Lower intracuff pressure of laryngeal mask airway in the lateral and prone positions compared with that in the supine position.

We compared the intracuff pressure (ICP) of a laryngeal mask airway (LMA) in the lateral and prone positions with that in the supine position. One hundred and eight patients, weighing 50-70 kg, scheduled for elective orthopedic and plastic surgery, were assigned to three groups, based on their body position during surgery. General anesthesia was induced and then a size 4 deflated LMA was inserted in each patient in the supine (group 1; n = 42), lateral (group 2; n = 45), or prone position (group 3; n = 21). The LMA cuff was inflated with 15 ml of air. Anesthesia was maintained without nitrous oxide, and the ICP was measured until LMA removal in the supine position. ICP in groups 2 and 3 was significantly lower than that in group 1 from immediately after insertion to the end of surgery. After surgery, turning from the lateral (group 2) or prone (group 3) position to the supine position significantly raised the ICP. Because the ICP is related to the seal pressure of the LMA and postoperative pharyngolaryngeal morbidity, we recommend evaluating and adjusting the ICP appropriately in each body position.